Dome and Screw Valves for Remotely Adjustable Gastric Banding Systems

ABSTRACT

An implantable device controls the movement of fluid to an inflatable portion of a gastric band. The implantable device includes a body. The body has an inlet, an outlet and a valve seat positioned between the inlet and the outlet. The body defines a fluid passage from the inlet to the outlet. The implantable device also includes a diaphragm. The diaphragm has one or more edges coupled to the body. The diaphragm is made of an elastomeric material and capable of being moved between a closed position that blocks the valve seat and does not allow the fluid to move from the inlet to the outlet and an open position that does not block the valve seat and allows the fluid to move from the inlet to the outlet.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Ser. No. 13/894,955, filed May15, 2013, now issued as U.S. Pat. No. 8,900,118, which is a continuationof U.S. patent application Ser. No. 12/712,952, filed Feb. 25, 2010,which is a continuation-in-part of U.S. patent application Ser. No.12/603,058, filed Oct. 21, 2009, now U.S. Pat. No. 8,366,602, whichclaims the benefit of U.S. Provisional Patent Application No.61/107,576, filed Oct. 22, 2008, the entire disclosure of each of theseapplications are incorporated herein by reference.

FIELD

The present invention generally relates to medical systems and apparatusand uses thereof for treating obesity and/or obesity-related diseases,and more specifically, relates to dome and screw valves for remotelyadjustable gastric banding systems.

BACKGROUND

Adjustable gastric banding systems provide an effective andsubstantially less invasive alternative to gastric bypass surgery andother conventional surgical weight loss procedures. Despite thesustained weight loss of invasive weight loss procedures, such asgastric bypass surgery, it has been recognized that sustained weightloss can also be achieved through a laparoscopically-placed gastricband, for example, the LAP-BAND® (Allergan, Inc., Irvine, Calif.)gastric band or the LAP-BAND APO (Allergan, Inc., Irvine, Calif.)gastric band. Generally, gastric bands are placed about the cardia, orupper portion, of a patient's stomach forming a stoma that restricts thefood's passage into a lower portion of the stomach. When the stoma is ofan appropriate size that is restricted by a gastric band, food held inthe upper portion of the stomach provides a feeling of satiety orfullness that discourages overeating. Unlike gastric bypass surgeryprocedures, adjustable gastric banding systems are reversible andrequire no permanent modification to the gastrointestinal tract.

Over time, a stoma created by the gastric band may need an adjustment inorder to maintain an appropriate size, which is neither too restrictivenor too passive. Prior art gastric banding systems provide asubcutaneous fluid access port connected to an expandable or inflatableportion of the gastric band. By adding fluid to or removing fluid fromthe inflatable portion by means of a hypodermic needle inserted into thefluid access port, the effective size of the gastric band can beadjusted to provide a tighter or looser constriction.

It would be desirable to allow for non-invasive adjustment of gastricband constriction, for example, without the use of the hypodermicneedle. Thus, remotely adjustable gastric banding systems capable ofnon-invasive adjustment are desired and described herein.

SUMMARY

In one example embodiment of the present invention, there is animplantable device that controls the movement of fluid to an inflatableportion of a gastric band. The implantable device includes a body. Thebody has an inlet, an outlet and a valve seat positioned between theinlet and the outlet. The body defines a fluid passage from the inlet tothe outlet.

The implantable device also includes a diaphragm. The diaphragm has oneor more edges coupled to the body. The diaphragm is made of anelastomeric material and capable of being moved between a closedposition that blocks the valve seat and does not allow the fluid to movefrom the inlet to the outlet and an open position that does not blockthe valve seat and allows the fluid to move from the inlet to theoutlet.

The implantable device also includes an actuator. The actuator isconfigured to apply a force on the diaphragm causing the diaphragm tomove from the closed position to the open position. The implantabledevice also includes a microcontroller coupled to the actuator, themicrocontroller configured to receive a telemetric signal from a remotetransmitter and control the actuator based on the telemetric signal.

In another example embodiment of the present invention, there is animplantable device that controls the movement of fluid to an inflatableportion of a gastric band. The implantable device includes a body. Thebody has an inlet, an outlet and a valve seat. The body defines a fluidpassage from the inlet to the outlet.

The implantable device also includes a valve seal. The valve seal hasone or more edges coupled to the body. The valve seal is made of anelastomeric material and is capable of being moved between an openposition that does not block the valve seat and allows the fluid to movefrom the inlet to the outlet and a closed position that blocks the valveseat and does not allow the fluid to move from the inlet to the outlet.

The implantable device also includes an actuator. The actuator ispositioned within the body. The actuator has an actuator body defining athreaded screw hole and a screw positioned within the threaded screwhole. The screw is configured to apply a force on the valve seal causingthe valve seal to move from the open position to the closed positionwhen the actuator receives a telemetric signal from an implantablemicrocontroller. A first telemetric signal may be used to move the valveseal from the open position to the closed position and a secondtelemetric signal may be used to move the valve seal from the closedposition to the open position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of a remotely adjustable gastricbanding system according to an embodiment of the present invention.

FIG. 2 illustrates an example configuration of the internal componentsof the high precision pump unit illustrated in FIG. 1 according to anembodiment of the present invention.

FIGS. 3A and 3B illustrate the filling and draining, respectively, of agastric band using the systems described herein according to anembodiment of the present invention.

FIGS. 4A and 4B illustrate cross-sectional views of an exemplary valvein a closed position and an open position according to an embodiment ofthe present invention.

FIGS. 5A and 5B illustrate cross-sectional views of an exemplary domevalve in a closed position and an open position according to anembodiment of the present invention.

FIGS. 6A and 6B illustrate cross-sectional views of an exemplary screwvalve in a closed position and an open position according to anembodiment of the present invention.

FIGS. 7A, 7B and 7C illustrate side views of examples of the couplingmechanism illustrated in FIGS. 6A and 6B according to variousembodiments of the present invention.

FIG. 8 is a flow chart of a method of controlling a dome valve accordingto an embodiment of the present invention.

FIG. 9 is a flow chart of a method of controlling a screw valveaccording to an embodiment of the present invention.

DETAILED DESCRIPTION

The present invention generally provides remotely adjustable gastricbanding systems, for example, for treatment of obesity and obesityrelated conditions, as well as systems for controlling inflation of agastric banding system.

Remotely adjustable gastric banding systems, otherwise referred to as aremotely adjustable band (RAB), include one or more medical devices, ora system, which allows a healthcare worker to adjust a gastric bandwithout requiring a hypodermic needle to be inserted into an implantedaccess port. The RAB may use a remote transmitter to send radiofrequencysignals or telemetric signals for powering and communicating with animplanted device of the RAB. The implanted device can fill or drain agastric band of the RAB as requested by the healthcare worker via theremote transmitter. In between filling and draining adjustments to thegastric band, the volume of fluid contained in the gastric band ideallyremains unchanged.

In one embodiment, a dome valve is used to pass and block fluid. Thedome valve has an actuator that can adjust an elastomeric diaphragm(e.g., a valve seal) to an open or closed position. The dome valve canbe used safely during magnetic resonance imaging (MRI) since the domevalve does not have a significant amount of ferromagnetic material. Theelastomeric diaphragm is also inexpensive and robust.

In another embodiment, a screw valve is used to pass and block fluid.The screw valve has a screw that can adjust a valve seal to multipleprecise positions, not just fully open or fully closed. The screw valvecan be used in a high pressure environment since no force is required tomaintain a position and because the screw can be driven to create atight seal.

FIG. 1 illustrates a perspective view of a remotely adjustable gastricbanding system 100 according to an embodiment of the present invention.The gastric banding system 100 includes a gastric band 102, a reservoir104, a high precision pump unit 106, a remote transmitter 108 and tubing110. The skin 122 of a human illustrates a separation betweenimplantable components and non-implantable components. As illustrated,the remote transmitter 108 (e.g., a remote controller unit) isnon-implantable, whereas the gastric band 102, the reservoir 104, thehigh precision pump unit 106, and the tubing 110 are implantable (e.g.,an implantable device), and can be implanted in the human usingconventional surgical techniques. The high precision pump unit 106 canbe used to replace or complement a conventional access port foradjusting inflation or deflation of the gastric band 102. In someembodiments, the system includes an override port 212 which can be used,for example, with a hypodermic needle 112, to fill and drain the gastricband 102.

The high precision pump unit 106 is connected to the reservoir 104 andthe gastric band 102 via the tubing 110, and can move precisely meteredvolumes of fluid (e.g., saline) in or out of the gastric band 102.Moving the fluid into the gastric band 102 causes inflation of at leastone bladder, or an inflatable portion 114 (e.g., inflatable member) andconstricts around the cardia, or upper portion of the stomach, forming astoma that restricts the passage of food into a lower portion of thestomach. This stoma can provide a patient with a sensation of satiety orfullness that discourages overeating. In contrast, moving the fluid outof the inflatable portion 114 of the gastric band 102 reduces thepressure around the cardia and allows the stoma to be at least partiallyreleased and allows the human to regain a hunger sensation.

The high precision pump unit 106 is implanted within a patient, andtherefore, is non-biodegradable. The encasement or housing of the highprecision pump unit 106 may be non-hermetically sealed or hermeticallysealed from the in situ environment (e.g., undisturbed environment) inthe patient and formed at least partially of any rugged plastic materialincluding, polypropylene, cyclicolephin co-polymer, nylon, and othercompatible polymers and the like or at least partially formed of anon-radiopaque metal. The housing has a smooth exterior shape, with nojagged edges, to minimize foreign body response and tissue irritation.The high precision pump unit 106 is also sterilizable, in oneembodiment, dry heat sterilizable before implantation.

The reservoir 104 may be a soft, collapsible balloon made of abiocompatible polymer material, for example, silicone, which holds areserve of a biocompatible fluid, for example, saline, to allow foradjustments in the size of the gastric band 102. In one embodiment, thereservoir 104 is fully collapsible and can contain the extra fluidrequired to increase the volume of the gastric band 102 to therapeuticlevels. Further, the reservoir 104 also may have excess capacity so thegastric band 102 may be fully drained into it without the reservoir 104being filled beyond its maximum capacity.

The reservoir 104 may represent one or both of a source reservoir and adrain reservoir, where the source reservoir provides fluid to thegastric band 102, and the drain reservoir receives fluid from thegastric band 102.

The fluids used within the systems of the present invention may includeany fluid that is biocompatible. The fluid has no adverse effect on thepatient in the unlikely event that a leak emanates from the system. Thefluid can simply be water or any biocompatible polymer oil such ascastor oil. In an example embodiment, the fluid is saline.

The tubing 110 is any biocompatible flexible tubing that does notdegrade in vivo (e.g., within the human). The tubing 110 is configuredto withstand hydraulic pressure up to about 30 psi (about 206 kPa)without leakage. This hydraulic pressure tolerance is true of the entirefluid path of the systems described herein. Although the systemsdescribed herein do not generally leak, if they do, fluid is not lost ata rate greater than about 0.2 cc/yr, or about 0.1 cc/yr.

Other biocompatible and biostable polymers which are useful for formingthe reservoir 104 and the tubing 110 include: polyolefins,polyisobutylene and ethylene-alphaolefin copolymers; acrylic polymersand copolymers, ethylene-co-vinylacetate, polybutylmethacrylate, vinylhalide polymers and copolymers, such as polyvinyl chloride; polyvinylethers, such as polyvinyl methyl ether; polyvinylidene halides, such aspolyvinylidene fluoride and polyvinylidene chloride; polyacrylonitrile,polyvinyl ketones; polyvinyl aromatics, such as polystyrene, polyvinylesters, such as polyvinyl acetate; copolymers of vinyl monomers witheach other and olefins, such as ethylene-methyl methacrylate copolymers,acrylonitrile-styrene copolymers, ABS resins, and ethylene-vinyl acetatecopolymers; polyamides, such as Nylon 66 and polycaprolactam; alkydresins; polycarbonates; polyoxymethylenes; polyimides; polyethers; epoxyresins, polyurethanes; rayon; rayon-triacetate; cellulose, celluloseacetate, cellulose butyrate; cellulose acetate butyrate; cellophane;cellulose nitrate; cellulose propionate; cellulose ethers; andcarboxymethyl cellulose.

The systems and apparatus described herein further include the remotetransmitter 108 (e.g., a remote controller unit), which provides accessto system data and functions, and can be an external, handheld, reusablebattery-powered device. The remote transmitter 108 can be made of anyrugged plastic material including polypropylene, cyclicolephinco-polymer, nylon, and other compatible polymers and the like. Theremote transmitter 108 is not implanted within the patient so hermeticsealing of the unit is not required. However, in one embodiment, theremote transmitter 108 is at least water resistant, if not waterproof,and can be cleaned using standard hospital disinfectants without damageto the unit.

Further, the remote transmitter 108 has a user interface including atleast one display 116 and at least one user input 118. In some exampleembodiments, the display 116 and the user input 118 are combined in theform of a touch screen with a color display. In other embodiments, thedisplay is grayscale. The remote transmitter 108 permits a clinician ora medical technician to navigate through menu driven screens used fordata entry, data collection, and controlling the high precision pumpunit 106.

The remote transmitter 108 is capable of communicating with the highprecision pump unit 106. “Capable of communicating” as used hereinrefers to the remote controller's ability to establish communicationswith the high precision pump unit 106 yet still have the ability tobreak communication and the systems described herein still function. Toestablish communication, in one example embodiment, once the remotetransmitter 108 is initialized, the display 116 shows a searching queryfor a nearby high precision pump unit 106. As the remote transmitter 108is brought into range of the high precision pump unit 106, a symboldisplays the strength of the communication link. Once stablecommunications have been acquired, the display 116 shows the serialnumber of the system so a clinician can verify they have the appropriatepatient records in hand. If the patient requires a tightening of thegastric band 102, the clinician can enter the amount of the desiredvolume increase. The remote transmitter 108 can also display the currentvolume within the gastric band 102 and indicate the new volume as thegastric band 102 fills. The display 116 can also indicate desired andactual volumes during draining of the gastric band 102.

To verify the appropriate adjustment has been made to the system, theclinician can set the remote transmitter 108 into a pressure monitormode and request that the patient drink water. The display 116 shows areal time graph of the pressure measured within the gastric band 102.This diagnostic tool may show higher pressures and warning messages ifthe gastric band 102 has been over-tightened.

The remote transmitter 108 can synchronize and charge when coupled witha charging cradle or docking station. This docking station provides theability to recharge a rechargeable battery of the remote transmitter 108and provides a link to download information to a personal computer suchas the adjustment history of a patient. Other data that can be stored onthe remote transmitter 108 and downloaded from the high precision pumpunit 106 includes, but is not limited to serial number, gastric bandsize, patient information, firmware version and patient adjustmenthistory. This data can be downloaded directly to a patient trackingdatabase for easy tracking.

Any data stored on the remote transmitter 108 or within the highprecision pump unit 106 can be electronically secured. In other words,security measures can be put in place to keep the data confidential,including communication between the high precision pump unit 106 and theremote transmitter 108. Security measures can include computer generatedalgorithms that prevent intrusion by outside parties.

The high precision pump unit 106 can contain a micro-fluidic pump withactive valves. In such an embodiment, the high precision pump unit 106is a passive device that can only be powered by the remote transmitter108 when it is in close proximity. For example, in one exampleembodiment, the remote transmitter 108 may be configured to power andcommunicate with the high precision pump unit 106 at any distance lessthan about 8 inches, in one embodiment less than about 4 inches (about10.2 cm) of tissue plus about 4 inches of air, and in another embodimentabout 2 inches (about 5.1 cm) of air. Power and communications can betailored to transmit over longer distances or can be tailored to havethe remote transmitter 108 placed on the skin adjacent to the highprecision pump unit 106.

Further, the remote transmitter 108 can provide an inductive power andtelemetric control through a transmission 124 to the high precision pumpunit 106. The remote transmitter 108 may be configured to providecontinuous power to the high precision pump unit 106. A dedicatedmicrocontroller within the remote transmitter 108 monitors the amount ofpower that is transmitted. Further still, a power management system maybe implemented to optimize energy transmission between the remotetransmitter 108 and the high precision pump unit 106 relative to theirseparation distance. For example, the power transmission mayautomatically decrease as the remote transmitter 108 is closer to thehigh precision pump unit 106, and may be increased as the distance isincreased. This minimizes wasted energy, and energy exposure to thepatient.

The systems and apparatus described herein use common surgicaltechniques to place the components in their respective positions withina patient. The surgical techniques may be identical or similar to thoseused in the placement of conventional gastric banding systems. Forexample, the gastric band 102 may be placed around the stomach usinglaparoscopic techniques, as known to those of skill in the art. Like aconventional access port, the high precision pump unit 106 may besutured onto the rectus muscle sheath or any other convenientlyaccessible muscle. In order to achieve a secure attachment of the highprecision pump unit 106, the unit shall be sutured to the rectus muscleand remain securely attached for forces below about 6 lbf, in oneembodiment below about 3 lbf (13.3 N). The tubing 110 from the highprecision pump unit 106 passes through the rectus muscle into theperitoneal cavity in the same manner as the tubing of a conventionalaccess port.

The systems and apparatus of the present invention further allow for aremotely controlled adjustment without needles, non-invasively, by usingthe remote transmitter 108. Also, should the remote transmitter 108 beunavailable, damaged, out of power, or in the event of an emergency, anadjustment of the gastric band 102 can be performed invasively using aneedle. By using the override port 212, a clinician can choose to usethe hypodermic needle 112, a standard needle, or a syringe foradjustments. If any of the electronics associated with the systems andapparatus described herein become inoperable, the override port 212 canbe used to add or remove fluid from the gastric band 102. The overrideport 212 and the hypodermic needle 112 can always be used to adjust thegastric band 102.

FIG. 2 illustrates an example configuration of the internal componentsof the high precision pump unit 106 illustrated in FIG. 1 according toan embodiment of the present invention. The housing of the highprecision pump unit 106 has an internal volume of between about 0.75 in³to about 1.6 in³. Exemplary internal features of the high precision pumpunit 106 that fit within the housing include a first valve 202, a secondvalve 204, a pump 206, a pressure/flow sensor 208, an electronics board210 including an antenna 211, and the override port 212. The internalcomponents of the high precision pump unit 106 can be arranged in anyfashion appropriate for delivering and removing precise amounts of fluidfrom the gastric band 102 and the reservoir 104.

The pump 206 can be actively or passively driven. If the pump 206 isactively driven, a local power source such as a battery (notillustrated) is provided to drive the pump 206. If the pump 206 ispassively driven, it may be inductively powered by a device external tothe high precision pump unit 106. In an exemplary configuration, thepump 206 is passively driven through inductive power from the remotetransmitter 108.

In one example embodiment, the pump 206 is an inductively powered,electrically driven, positive displacement piezoelectric pump. The pump206 provides a means to move fluid into the gastric band 102.

The pump 206 can move fluid from the reservoir 104 to the gastric band102 at rates higher than about 0.5 cc/min, for example, higher thanabout 1 cc/min for band pressures less than about 20 psi (about 138 kPa)relative to the reservoir pressure. Alternatively, fluid can be drainedfrom the gastric band 102 to the reservoir 104 at rates higher thanabout 0.5 cc/min, for example, higher than about 1 cc/min for bandpressures above about 0.2 psi (about 1.38 kPa).

The first valve 202 and the second valve 204, illustrated in FIG. 2, canbe any valve known in the art to allow precise delivery of fluid andprecise flow rates therethrough. In one embodiment, the first valve 202and the second valve 204 only allow fluid to move in one direction,therefore, the two valves are situated in parallel with the highprecision pump unit 106 allowing fluid to drain back from the gastricband 102. Further, the first valve 202 and the second valve 204 shouldhave a precision orifice that restricts the flow rate to awell-characterized, precise amount.

The gastric banding system 100 may further comprise at least one flow orpressure sensor 208 disposed, for example, within or adjacent to thehigh precision pump unit 106. In an exemplary embodiment, two pressuresensors are situated within the fluid pathway between the first valve202 and the second valve 204 and the gastric band 102. During a no-flowcondition, both of the pressure sensors may be used to measure pressurethereby providing the benefits of redundancy and averaging.

For example, sensing or measuring the pressure within the fluid pathwayof the gastric banding system 100 provides diagnostic uses. A cliniciancan measure pressure while a patient drinks water, recording andanalyzing resulting pressure fluctuations which can help determine ifthe gastric band 102 is too restrictive. Whether the gastric band 102 istoo restrictive can also be confirmed by the patient's response(generally discomfort) upon drinking the water, and can then beappropriately adjusted. Further, sensing or measuring pressure in thegastric banding system 100 can be useful in diagnosing system leaks orobstructions. For example, if the pressure consistently drops over anextended period of time, the clinician can diagnose a leak within thesystem and plan for an appropriate treatment to fix the problem. Incontrast, if there is an obstruction within the system with a sustainedpressure rise over time, the clinician can diagnose an obstructionwithin the system and plan for an appropriate treatment to fix theproblem.

The override port 212, as illustrated in FIGS. 1 and 2, is an optionalfeature of some of the embodiments of the present invention. Theoverride port 212 can be manufactured from a metal or a non-radiopaquematerial and is accessible by insertion of the hypodermic needle 112 (inFIG. 1) through a self-sealing septum 214 (in FIG. 2). The override port212 allows a clinician to use the hypodermic needle 112 or a standardsyringe to fill or drain the gastric band 102. Further, the overrideport 212 may be located on the distal end 216 of the high precision pumpunit 106, for example, at a position substantially opposite from theproximal end 218 where the tubing 220 extends from the high precisionpump unit 106. This placement of the override port 212 thereby reducespossible occurrences of a needle damaging the tubing 220. An extensionbody 222 emanating from the high precision pump unit 106 furtherprotects the tubing 220 from accidental needle sticks.

The high precision pump unit 106 can be a passive device which may beentirely controlled and powered by the remote transmitter 108. Theantenna 211 on the electronics board 210 is housed within the highprecision pump unit 106 and the remote transmitter 108 is coupled toallow the transmission 124 of signals and power through the skin 122 (asillustrated in FIG. 1). The power issued from the remote transmitter 108is continually monitored by a dedicated microprocessor to ensure thatpower transmission is minimized to the lowest level required foroperation. To minimize the transmission 124 of power and to optimize thetransmission 124 of command communication, the high precision pump unit106 and the remote transmitter 108 have a channel frequency dedicated tocommand communication and a separate channel frequency dedicated topower transmission. The command communication can be configured, forexample, to take place at about 402-406 MHz while the powertransmission, for example, takes place at about 400 kHz. This commandcommunication adheres to the frequency and power standards set by theMedical Implant Communications Service. To ensure accuracy,communication and control commands are verified by error checkalgorithms prior to data reporting or command implementation.

A portion of the electronics board 210 within the high precision pumpunit 106 is devoted to conditioning and managing the power received atthe antenna 211 or from a local battery. Communication electronicsmanage the bidirectional transmissions with timing verification anderror checking. Controller circuits of the electronics board 210 sendcommands to the first valve 202, the second valve 204, the pump 206, andthe pressure/flow sensor 208 and receive data back from thepressure/flow sensor 208. The electronics board 210 can be encased in abiocompatible sealant if further protection, or redundant protection, isnecessary.

In one example embodiment, the systems and apparatus described hereinare configured and structured to be compatible with MRI, or MRI safe,at, for example 1.5 T. In the exemplary embodiment shown, the highprecision pump unit 106 is entirely inductively powered. The systemsutilize no permanent magnets, no long metallic wires or leads, and aminimal or negligible amount of ferrous or ferromagnetic material. Thesystems are substantially free or contain substantially no ferromagneticmaterials. Substantially no ferromagnetic materials refers to materialscontaining less than about 5%, in one embodiment, less than about 1% or0.1% (w/w) of ferromagnetic material. The resulting systems are thus MRIsafe given standard specifications regulating translational androtational attraction, MRI heating, and imaging artifacts. In oneembodiment, all materials selected for the systems are selected to becompatible and safe in an MRI environment.

Further, the inductive powering of the high precision pump unit 106requires that energy be passed through body tissue. Since the bodytissue absorbs a small amount of the energy passing through it, theheating of the tissue can be proportional to the total energytransferred. To ensure that the systems meet standards to minimizetissue heating (below 2° C. above body temperature per ISO 45652), thesystems described herein have been designed to use very little power tomove the fluid within the system and do not cause excessive heating ofthe patient's tissue.

The pressure/flow sensor 208 can monitor pressure inside the gastricband 102 as needed. Using the remote transmitter 108 to communicate withthe high precision pump unit 106, a clinician can monitor pressureinside the gastric band 102, for example, in “real time” during anadjustment of the constriction within the gastric band 102. This willallow the clinician to observe the response of the gastric band 102 to apatient's adjustment. This may permit a new modality for the gastricband 102 adjustment management to monitor pressure as well as volumeduring an adjustment. With these new pressure sensing capabilities, theclinician can make a determination of whether there is a leak within thesystem (e.g., zero pressure reading) or whether there is an obstructionin the system (e.g., prolonged pressure rise).

In an example embodiment, the high precision pump unit 106 includes afirst fluid line including a first pump for passing fluid in a firstdirection and a second fluid line in parallel with the first fluid lineincluding a first valve and a second pump for passing fluid in anopposing direction. In another example embodiment, the second pump isnot needed because the gastric band 102 provides enough pressure themove the fluid to the reservoir 104. The parallel line configurationallows for filling and draining of the gastric band 102 with a minimalnumber of components and minimal complexity.

The systems and apparatus described herein can achieve at least one ofthe following features. The total time required to complete a fill ordrain of the gastric band 102 does not exceed about 10 minutes, and inone embodiment, about 5 minutes.

The systems are able to adjust the volume in the gastric band 102accurately to within about 0.1 cc or about 10%, whichever is greater.The pressure/flow sensor 208 has a resolution between about 0.010 psi toabout 0.025 psi, and in one embodiment, about 0.019 psi (about 130 Pa).

In one example embodiment of the present invention, components of thesystems can be replaced without replacing the entire system andsubjecting patients to overly invasive surgeries to replace entiresystems when a single component is defective or damaged. For example, ifthe high precision pump unit 106 becomes damaged, it can be replacedindependently of other components. Alternatively, if the gastric band102 becomes damaged, it can be replaced independently of othercomponents. The same is true of the tubing 110 and the reservoir 104.Although components can be disconnected for single part replacement,components shall not become dislodged from the tubing 110 for tubingpull-off forces less than about 10 lbf, and in one embodiment, less thanabout 5 lbf (22.2 N).

The systems described herein meet at least one safety specification. Forexample, in the event of any failure of the systems, either no change inthe gastric band 102 tightness or a loosening of the gastric band 102results. Further, the high precision pump unit 106 is biocompatible forlong term implantation and the remote transmitter 108 is biocompatiblefor transient use both per ISO 10993. The systems are designed to haveno significant interaction or interference with other electronics in anyof the following modalities: implantable energy sources such asdefibrillators and pacemakers; internal energy sources such aselectrosurgical instruments; external energy sources such as ultrasound,x-rays and defibrillators; and radiofrequency signals such as pacemakerprogrammers and neurostimulators.

Example 1 Implantation of a Gastric Band System

A 40 year old female is diagnosed by her clinician as obese, weighing510 lbs. The clinician suggests to the patient that she consider thegastric banding system 100 according to the present invention. Sheagrees and undergoes the implantation procedure. The gastric band 102 isimplanted around her cardia thereby creating a stoma. The high precisionpump unit 106 is sutured onto the rectus muscle sheath and the tubing110 and the reservoir 104 passes through the rectus muscle into theperitoneal cavity and connects to the gastric band 102. The gastricbanding system 100 comes pre-filled, so there is no need for theclinician to fill the gastric banding system 100 during the surgicalprocedure. The patient is sutured and sent to recovery.

Example 2 Adjustment of a Gastric Band System

The female patient of Example 1, after the completion of the surgicalimplantation, has her gastric band system 100 properly adjusted by herclinician. The clinician holds the remote transmitter 108 to the skin122 adjacent to the rectus muscle where the high precision pump unit 106is located and initiates communication between the devices. An initialpressure of zero is displayed for the gastric band 102 as no fluid hasbeen added to the gastric band 102. The clinician begins to fill thegastric band 102 using saline housed within the reservoir 104 at a rateof about 1 cc/min and the entire filling takes less than about 5minutes.

After filling, to about 10 psi, the patient is instructed to drink aglass of water in order to properly assess the proper inflation pressureof the gastric band 102 to ensure it has not been over inflated. Uponconfirmation that the gastric band 102 is properly inflated, theprocedure is completed and the patient returns to her normal life.

The patient instantly notices that she is much less hungry than shepreviously had been and is consistently consuming less food as herappetite has been decreased. She returns to her clinician's office for afollow-up visit three months after her implantation and initial gastricband filling and she has lost 20 pounds. A year later, she has lostnearly 60 lbs.

The gastric banding system 100 generally functions as follows. When aclinician uses the remote transmitter 108 to adjust the gastric band102, the high precision pump unit 106 initiates a sequence of events tomove a precise amount of fluid in the desired direction, where thefilling is discussed in FIG. 3A and the draining is discussed in FIG.3B.

FIG. 3A illustrates the filling of the gastric band 102 according to anembodiment of the present invention. Just before pumping is initiated,the second valve 204, in line with the pump 206, is opened. The pump 206creates a differential pressure to draw fluid out of the reservoir 104and into the gastric band 102. The first valve 202 and the pressure/flowsensor 208 are closed or not engaged. The reservoir 104 is collapsibleand does not impede the outward flow of fluid. Further, the reservoir104 is sized such that when filled to the maximum recommended fillvolume, there is a slight vacuum therein. Once the proper amount offluid has been transferred from the reservoir 104 to the gastric band102, the electronics board 210 (or circuitry thereon) shuts off the pump206 and closes the second valve 204. The gastric band 102 now assumesthe new higher pressure and fluid.

Referring to FIG. 3B, if the clinician decides to there is a need toloosen the gastric band 102, fluid is released from the gastric band 102and returned to the reservoir 104. Once the high precision pump unit 106receives a drain command from the remote transmitter 108, the firstvalve 202 behind the pressure/flow sensor 208 opens. The fluid istransferred from the gastric band 102 through the pressure/flow sensor208 and the first valve 202 and into the reservoir 104. The amount offluid released from the gastric band 102 can be monitored and determinedby the pressure/flow sensor 208. Once the correct volume of fluid hasbeen transferred, the first valve 202 is closed. With both the firstvalve 202 and the second valve 204 closed, the volume in the gastricband 102 is maintained and the pressure in the gastric band 102 can bemeasured accurately using the pressure/flow sensor 208.

When compared to conventional gastric banding systems having standardaccess ports which exclusively require syringe access (as opposed tobeing optional), the presently described systems and apparatus offerseveral benefits. First, the conventional access ports are located undera thick layer of fatty tissue, which is generally the case as thedevices are generally used to treat obesity, and the access port can bedifficult to locate. The present systems reduce or eliminate the needfor (or to locate) the access port, as the use of the remote transmitter108 removes the need for adjustment using the hypodermic needle 112.

Secondly, when accessing the access port in conventional systems, theambiguity on its location may lead to damage by accidentally puncturingthe tubing 110 which connects the access port 212 to the gastric band102. This can require a revision surgery in order to repair thepunctured tubing 110. Further, when a conventional access port cannot belocated by palpation, x-ray imaging may be required to guide a needleinto the access port. Such imaging practices put a patient at risk forx-ray radiation exposure. The present systems and apparatus remove theneed for these unnecessary procedures and save the patient from x-rayradiation exposure. The present systems and apparatus are compatiblewith magnetic resonance imaging (MRI), which is much safer for apatient.

In the unlikely event that the override port 212 of the presentinvention needs to be used, the override port 212 may be located awayfrom the tubing connection to the gastric band 102 to reduce thepotential for tubing needle sticks. The high precision pump unit 106 hasgeometry and a rigid case that can be structured to facilitate the userin locating the override port 212 when needed.

FIGS. 4A and 4B illustrate cross-sectional views of an exemplary valve400 in a closed position (FIG. 4A) and an open position (FIG. 4B)according to an embodiment of the present invention. The valve 400 maybe used in place of one or both of the first valve 202 and the secondvalve 204.

Referring to FIG. 4A, the valve 400 is biased in a closed position, forexample, by a spring preload force 402 acting on a seal 404, forexample, a flexible silicone seal 404. For example, the spring preloadforce 402 pushes the flexible silicone seal 404 into sealing engagementwith a valve seat 406. When the valve 400 is sealed as shown in FIG. 4A,fluid cannot pass from a valve inlet 408 to a valve outlet 410.

Now referring to FIG. 4B, when fluid flow is desired, a signal is sentto a valve actuator (not shown), which removes the spring preload force402 and permits the flexible silicone seal 404 to relax or move upwardinto an open position, out of sealing engagement with the valve seat406. The fluid is then free to flow from the valve inlet 408 to thevalve outlet 410 until the valve 400 is closed, for example, byreapplication of the spring preload force 402.

FIGS. 5A and 5B illustrate cross-sectional views of an exemplary domevalve 500 in a closed position (FIG. 5A) and an open position (FIG. 5B)according to an embodiment of the invention. In one embodiment, the domevalve 500 is an implantable device that controls the movement of fluidto the inflatable portion 114 of the gastric band 102. The dome valve500 may be used in place of one or both of first valve 202 and thesecond valve 204.

The dome valve 500 is designed to be implanted into a patient, and thusmay be referred to as a micro valve. In an embodiment, the dome valve500 has a length of about 15 mm (e.g., 10-25 mm range) and an about 10mm outer diameter (e.g., 7-15 mm range). In one embodiment, the domevalve 500 is a radially symmetric shape (e.g., disk, tube, rod, etc.).However, the dome valve 500 can be any shape (e.g., circular, square,rectangular, etc). The dome valve 500 can include a body 560, anactuator 505, a cap 510, and a diaphragm 520.

The body 560 has an inlet component 530, an outlet component 535, and abottom component 550. The inlet component 530, the outlet component 535,and the bottom component 550 have been identified for illustrativepurposes and may not be separate components from the body 560. An inlet540, which is a fluid entrance into the body 560, is defined between theinlet component 530 and the bottom component 550. An outlet 545, whichis a fluid exit from the body 560, is defined between the outletcomponent 535 and the bottom component 550.

The inlet component 530 and the bottom component 550 form a valve seat570. The valve seat 570 can be the surfaces (e.g., the tips) of theinlet component 530 and the bottom component 550 which provide sealingwhen the diaphragm 520 is placed against and in contact with the inletcomponent 530 and the bottom component 550. In one embodiment, thevertical column of the inlet component 530 and the bottom component 550define the valve seat 570. The vertical columns may be short segments(e.g., 1.5 mm) of plastic or metal tubing (e.g., stainless steel).

The actuator 505 is configured to apply a force (e.g., stress) on thecap 510 causing the diagraph 520 to move from the closed position (FIG.5A) to the open position (FIG. 5B) when the actuator 505 receives atelemetric signal 124 (e.g., electrical energy) from the remotetransmitter 108. The force includes a smaller downward force 555 to keepthe valve 500 in a closed position (FIG. 5A) and a larger downward force565 to keep the valve 500 in an open position (FIG. 5B). In anembodiment, the smaller force 555 is less than 10 newtons. In anembodiment, the larger force 565 is between 10-100 newtons. In anotherembodiment, the larger force 565 is between 15-45 newtons.

FIG. 5A illustrates the actuator 505 applying the smaller force 555(e.g., 0 newtons, little or no downward force, a reduced in force, ade-energized state), which is low enough to keep the valve 500 in theclosed position. In particular, when the actuator 505 applies thesmaller force 555, the cap 510 receives little or no downward force oncap edges 515. Since the cap edges 515 are adjacent to the diaphragmedges 525, the diaphragm edges 525 also receive little or no downwardforce. As such, the diaphragm center 527 of the diaphragm 520 remainssitting on (or relaxed onto) the valve seat 570, blocking fluid fromflowing from the inlet 540 to the outlet 545.

FIG. 5B illustrates the actuator 505 applying a large force 565 (e.g.,an energized state) that compresses (e.g., squeezes) the diaphragm edges525 between the cap 510 and the body 560. The large force 565 is greatenough that the material on the diaphragm edges 525 is compressed, withthe cap 510 blocking diaphragm edges 525 from expanding outward, thediaphragm is expanded inward such that the diaphragm center 527 is movedup off the valve seat 570 due to a build-up of material. This opens apassage from the inlet 540 to the outlet 545 and permitting fluid flowin the valve 500 as shown by fluid flow indicators 575. When a downwardforce is applied, the diaphragm center 527 moves in a substantiallyopposite direction to the downward force.

The actuator 505 can take many forms (e.g., solenoids, stepper motors,piezoelectric actuator, electroactive polymer, etc.) as dictated by thespecific application. In one embodiment of the RAB, the actuator 505 isa piezoelectric actuator. In another embodiment, the actuator 505 is anelectroactive polymer.

The cap 510 may be positioned between the diaphragm 520 and the actuator505. The cap 510 has one or more cap edges 515 (e.g., cap ends). The capedges 515 direct the small force 555 and the large force 565 from theactuator 505 to the diaphragm 520. In one embodiment, the cap 510 ispart of the actuator 505.

The diaphragm 520, which may be referred to as a valve seal, ispositioned between the cap 510 and the body 560. The diaphragm 520 has adiaphragm center 527 (e.g., a body) and one or more diaphragm edges 525(e.g., ends of the diaphragm 520) coupled to the body 560.

The diaphragm 520 (e.g., valve seal) has an open position (FIG. 5B) anda closed position (FIG. 5A). When the diaphragm 520 is in the openposition, the diaphragm 520 does not block the valve seat 570 andtherefore allows the fluid to move from the inlet 540 to the outlet 545.Conversely, when the diaphragm 520 is in a closed position, thediaphragm 520 blocks the valve seat 570 and does not allow the fluid tomove from the inlet 540 to the outlet 545.

In one embodiment, the diaphragm 520 is made of an elastomeric material.The elastomeric material includes silicon and any other material that isstretchy like a rubber band. For example, the elastomeric materialincludes flexible materials, naturally occurring elastic substances(e.g., natural rubber), and synthetically produced substances (e.g.,silicon, butyl rubber, neoprene).

The elastomeric material can be stretched across the valve seat 570 toprovide a seal and can buckle to create a gap 526 above the valve seat570. In an embodiment, the gap 526 below the diaphragm 520 issubstantially less than 1 mm off the valve seat 570. In one embodiment,the gap 526 is about 0.03 mm. In one embodiment, the range for the gap526 is between about 0.01 mm to about 0.25 mm. In another embodiment,the range for the gap 526 is between about 0.01 mm to about 0.10 mm.

In one embodiment, the diaphragm 520 is circular, although any shape ispossible (e.g., a thin strip, rectangular, etc).

The dome valve 500 has numerous advantages over conventional valves. Thedome valve 500 contains no ferromagnetic material as is commonly used inconventional valves (e.g., solenoid valves). As a result, the dome valve500 advantageously can be safely used in conjunction with magneticresonance imaging (MRI) scanning.

Additionally, the dome valve 500 advantageously is not concentric withthe diaphragm, unlike conventional valves which have a concentric shapedseal which results in high susceptibility to leakage and contaminationto the moving parts of the valve.

Advantageously, both the diaphragm 520 and the cap 510 restrict fluidfrom contacting the moving valve components, such as the actuator 505.This allows the dome valve 500 to be used in a system where the fluid ishighly corrosive to the moving parts and can be used where the movingparts rub and create contaminants that must be keep free from the fluid,because the dome valve 500 protects the moving valve components fromcontamination.

Dome valve 500 advantageously can be inexpensively manufactured, duepartly to the mechanical linkage, while still being robust andefficient. Opening the valve 500 requires very little stroke or travelfrom the actuator 505 to produce a suitably large upward deflection inthe diaphragm 520. In contrast, conventional valves use energyinefficient methods such as forming a seal for a valve by heating amembrane comprised of two materials with different coefficients oflinear thermal expansion.

Also, the dome valve 500 achieves a low leak/leakage rate when in theclosed position (e.g., closed/sealed tightly) compared to conventionalvalves and achieves a high flow rate when in the open position. Further,the dome valve 500 minimizes the space required for the implanted devicebecause the dome valve 500 can be smaller than other implantabledevices.

FIGS. 6A and 6B illustrate cross-sectional views of an exemplary screwvalve 600 in a closed position (FIG. 6A) and an open position (FIG. 6B)according to an embodiment of the present invention. The screw valve 600is part of the RAB and may be used in place of one or both of the firstvalve 202 and the second valve 204. The screw valve 600 is designedsmall enough to be implanted into a patient, and thus may be referred toas a micro valve. In an embodiment, the screw valve 600 has a length ofapproximately 30-50 mm and an about 10 mm outer diameter (e.g., 7-15 mmrange). In comparison to the dome valve 500 embodiment discussed above(10-25 mm length, 10 mm outer diameter), the screw valve 600 is almosttwice as long, but has the same outer diameter.

The screw valve 600 in accordance with one embodiment of the presentinvention generally includes a body 660, a screw 615, a screw actuator605, a coupling mechanism 610, a valve seal 620, and a valve seat 670.

The body 660 houses the components of the screw valve 600. The body 660also has an inlet 640 and an outlet 645. The inlet 640 may be incommunication with the reservoir 104 and the outlet 645 may be incommunication with the inflatable portion 114 of the gastric band 102,or vice-versa, using suitable fluid port connectors, not shown.

The screw 615 includes a lead screw (where lead means a type of screw,and does not mean the material lead as used in a graphite pencil), powerscrew, translation screw. The screw 615 can be designed to translateradial (e.g., circular) motion/movement into linear (e.g.,translational) motion/movement. The screw 615 is configured to apply aforce on the valve seal 620 to cause the valve seal 620 to move from anopen position (FIG. 6B) to a closed position (FIG. 6A) when the screwactuator 605 receives a telemetric signal 124 from the remotetransmitter 108.

The screw actuator 605, positioned within the body 660 of the screwvalve 600, has an actuator body defining a threaded screw hole 606. Thescrew 615 is positioned within the threaded screw hole 606.

In one embodiment, the screw actuator 605 is a motor. In anotherembodiment, the motor may be positioned within the screw actuator 605.In another embodiment, the motor is external to the body 660 for movingthe screw 615.

The motor (not shown) may also be included in the screw valve 600 andcoupled to the screw 615 for moving the screw 615 within the threadedscrew hole 606. The motor can be a DC motor, an AC motor, a solenoid, astepper motor, a piezoelectric actuator, a piezoelectric driver, and anelectroactive polymer. In one embodiment, the motor is selected to bethe same type of motor used elsewhere in the implantable system. Themotor can be configured to move the screw 615 to at least two positionsso that the valve seal 620 can be moved to at least two positionsdepending on the telemetric signal 124 sent from the remote transmitter108 to the actuator 605.

The coupling mechanism 610, positioned between the valve seal 620 andthe screw 615, decouples a rotational motion of the screw 615. In oneembodiment, the coupling mechanism 610 may be securely fastened or fixedto the valve seal 620 so that the coupling mechanism 610 does not rotatewith the rotation of the screw 615. The screw 615 moves forward andbackward (or upward and downward) through both rotational andtranslational motion. However, to prevent damage to the valve seal 620,the valve seal 620 should only receive translational motion (notrotational motion). The coupling mechanism 610 decouples the rotationalmotion of the screw 615 but transmits the translational motion. Thecoupling mechanism 610 is illustrated as being a tappet, but can alsoinclude a ball bearing, a bellows unit, etc., as illustrated in FIGS.7A-7C.

The valve seal 620 has one or more edges 621 coupled to the body 660.The valve seal 620 is capable of being moved from an open position thatis spaced apart from the valve seat 670 and does not block a fluid(e.g., saline) from flowing from the inlet 640 to the outlet 645 to aclosed position that blocks or contacts the valve seat 670 and does notallow the fluid to move from the inlet 640 to the outlet 645. The valveseal 620 can be in the closed position, the open position, and apartially-open position, which is between the closed position and theopen position.

The valve seal 620, like the diaphragm 520, is made of an elastomericmaterial. In one embodiment, the elastomeric material is silicon.However, any material that is stretchy like a rubber band can be used.For example, the elastomeric materials include flexible materials,naturally occurring elastic substances (e.g., natural rubber), andsynthetically produced substances (e.g., silicon, butyl rubber,neoprene).

The valve seat 670 provides an opening for the valve seal 620 to closeor open. To close the screw valve 600, a command signal (e.g., atelemetric signal) is sent to the screw actuator 605 which drives thescrew 615 (and the coupling device or mechanism 610) into the valve seal620 to press the valve seal 620 onto the valve seat 670. To open thescrew valve 600, a command signal is sent to the screw actuator 605which drives the screw 615 (and the coupling device or mechanism 610)away from the valve seal 620 to decompress or move the valve seal 620away from the valve seat 670.

The pressure/flow sensor 208 may also be included in or coupled to thescrew valve 600. For example, one or both of the flow sensor and/or thepressure sensor can be coupled to the valve seat 670 for determining andadjusting an amount of the fluid flowing between the inlet 640 and theoutlet 645.

FIG. 6A illustrates the screw 615 displacing the valve seal 620 onto thevalve seat 670 to block the fluid from flowing from the inlet 640 to theoutlet 645.

FIG. 6B illustrates the screw 615 moved upward such that the valve seal620 is not touching the valve seat 670 to allow the fluid to flow fromthe inlet 640 to the outlet 645 as shown by fluid flow indicators 675.The fluid can also flow in the opposite direction as shown by the fluidflow indicators 675.

The lead screw valve 600 provides many advantages when used for thegastric banding system 100. For example, the screw valve 600 achieves alow leak/leakage rate when closed (e.g., closed/sealed tightly) comparedto conventional valves and a high flow rate during adjustment. The screwvalve 600 is also easier to manufacture than other implantable devices(such as the dome valve 500).

An additional advantage, is that the screw valve 600 can remain inposition (e.g., fully open, partially open, tightly closed) in thepresence of very high constant and intermittent pressures present fromthe inlet 640 and the outlet 645. For example, the screw valve 600 canhandle high pressures, such as 30 psi. The screw valve 600 can resisthigh pressures by being overdriven and by being a normally-still valve.

If the screw 615 is intentionally overdriven, the screw 615 pressestightly against the coupling mechanism 610, which presses tightlyagainst the valve seal 620, which presses tightly against the valve seat670. The term overdriven means that the screw 615 is driven just beyondthe point where the valve seal 620 contacts the valve seat 670. Thephrase “just beyond” means a point where force is generated. Even thoughit's not possible (without damage) to move the valve seal 620 beyond thepoint that it touches the valve seat 670, it is possible to generateforce. For example, forces develop in the motor and forces developloading up the motor. These forces creating a force balance between thevalve seal 620 and the valve seat 670. In one embodiment, “just beyond”is a point where an additional force is required from the motor.

Even though the screw 615 drives the valve seal 620 hard into the valveseat 670, in one embodiment, the valve seal 620 is made of a softmaterial (e.g., silicon) and the valve seat 670 is made of a hardmaterial (e.g., polished stainless steel) such that the two materialscan be pressed together without resulting in substantial damage ormarring. This tight seal blocks fluid, including fluid under highpressure. The screw 615 can optionally be reversed to relieve anyunwanted excess pressure on the screw 615, the coupling mechanism 610,the valve seal 620, and the valve seat 670.

Another advantage of the screw valve 600 is that the screw 615 canresist the opening and closing in the presence of steady or highpressure, without requiring an additional energy, because the screwvalve 600 is a normally still valve (as oppose to normally open ornormally closed). Thus, in the absence of a drive command, the screwactuated valve will remain in whichever state it was left, whether thatwas fully open, partially open, or fully closed.

An additional advantage of the screw valve 600 is the amount ofpositions available to regulate fluid flow. The screw valve 600 can befully open, fully closed, or anywhere in between, providing significantflexibility in designing actuation drive characteristics. The fluid flowrate can be adjusted by partially opening the screw valve 600. The screwseal 620 can occupy any position by making precise and incrementaladjustments to the screw 615. In one embodiment, the screw valve 600 isused in a closed loop system, where a sensor (e.g., flow sensor, apressure sensor, etc.) is used to adjust the position of the screw 615to regulate the fluid flow from the inlet 640 to the outlet 645.

FIGS. 7A, 7B and 7C illustrate side views of examples of the couplingmechanism 610 illustrated in FIG. 6 according to various embodiments ofthe present invention. FIG. 7A illustrates a tappet 705 as the couplingmechanism 610. The tappet 705 can be a sliding rod for moving a valve.The tappet 705 touches the screw 615, and connects or rides on the screw615. The tappet 705 allows an intentional rotational slippage betweenthe tappet 705 and the screw 615 to decouple the rotational motion.

FIG. 7B illustrates a ball 710 along with the tappet 705 as the couplingmechanism 610. The ball 710 is located between the screw 615 and thetappet 705. The ball 710 provides two surfaces designed to allow anintentional rotational slippage between the screw 615 and the valve seal620. Having two surfaces for slippage is advantageous because onesurface may bind-up due to particulate contamination (e.g., particlesfrom the screw 615 or the tappet 705) or manufacturing imperfection(e.g., molding flash, burrs, etc.). The ball 710 can be a ball bearing.

FIG. 7C illustrates a bellows unit 715 as the coupling mechanism 610used with the screw 615. The bellows unit 715 can isolate the screw 615from the valve seal 620. Without the bellows unit 715, the screw 615would rotate and rub against a surface of the valve seal 620 generatingparticulates which are further rubbed against the valve seal 620. Sincethe valve seal 620 can be sensitive and not designed to be rubbed withparticulates, the bellows unit 715 advantageously keeps all the possiblegenerated particulates enclosed and sealed away from the valve seal 620.

FIG. 8 is a flow chart of a method of using the dome valve 500 tocontrol the movement of fluid between the reservoir 104 and theinflatable portion 114 of the gastric band 102.

The process starts at step 800. At step 805, the dome valve 500 receivesa telemetric signal from the remote transmitter 108. Alternatively, thedome valve 500 can receive a signal from an implanted microcontroller.The implanted microcontroller may be part of, coupled to or locatedwithin the actuator 505. The implanted microcontroller can receive atelemetric signal from the remote transmitter 108. Next, the actuator505 applies a downward force on the diaphragm 520 to open the dome valve500 at step 810. The downward force is applied onto the diaphragm edges525 of the diaphragm 520 in the dome valve 500, lifting up the diaphragmcenter 527, and allowing fluid to flow through the dome valve 500.

At step 815, the actuator 505 reduces the downward force on thediaphragm 520 to close the dome valve 500. The downward force is reducedon the diaphragm edges 525 of the diaphragm 520 in the dome valve 500,lowering the diaphragm center 527, and blocking fluid from flowingthrough the dome valve 500. The process ends at step 820.

FIG. 9 is a flow chart of a method of using the screw valve 600 tocontrol the movement of fluid between the reservoir 104 and theinflatable portion 114 of the gastric band 102.

The process starts at step 900. At step 905, the screw valve 600receives a telemetric signal from the remote transmitter 108.Alternatively, the dome valve 600 can receive a signal from an implantedmicrocontroller. The implanted microcontroller may be part of, coupledto or located within the screw actuator 605. The implantedmicrocontroller can receive a telemetric signal from the remotetransmitter 108. At step 910, the screw actuator 605 turns the screw 615in one direction to increase a force on the valve seal 620 to close thescrew valve 600.

Then, the screw actuator 605 turns the screw 615 in the oppositedirection to decrease the force on the valve seal 620 to open the screwvalve 600. The process ends at step 920.

Unless otherwise indicated, all numbers expressing quantities ofingredients, properties such as molecular weight, reaction conditions,and so forth used in the specification and claims are to be understoodas being modified in all instances by the term “about.” Accordingly,unless indicated to the contrary, the numerical parameters set forth inthe specification and attached claims are approximations that may varydepending upon the desired properties sought to be obtained by thepresent invention. At the very least, and not as an attempt to limit theapplication of the doctrine of equivalents to the scope of the claims,each numerical parameter should at least be construed in light of thenumber of reported significant digits and by applying ordinary roundingtechniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contains certainerrors necessarily resulting from the standard deviation found in theirrespective testing measurements.

The terms “a,” “an,” “the” and similar referents used in the context ofdescribing the invention (especially in the context of the followingclaims) are to be construed to cover both the singular and the plural,unless otherwise indicated herein or clearly contradicted by context.Recitation of ranges of values herein is merely intended to serve as ashorthand method of referring individually to each separate valuefalling within the range. Unless otherwise indicated herein, eachindividual value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein isintended merely to better illuminate the invention and does not pose alimitation on the scope of the invention otherwise claimed. No languagein the specification should be construed as indicating any non-claimedelement essential to the practice of the present invention.

Groupings of alternative elements or embodiments of the inventiondisclosed herein are not to be construed as limitations. Each groupmember may be referred to and claimed individually or in any combinationwith other members of the group or other elements found herein. It isanticipated that one or more members of a group may be included in, ordeleted from, a group for reasons of convenience and/or patentability.When any such inclusion or deletion occurs, the specification is deemedto contain the group as modified thus fulfilling the written descriptionof all Markush groups used in the appended claims.

Certain embodiments of the present invention are described herein,including the best mode known to the inventors for carrying out thepresent invention. Of course, variations on these described embodimentswill become apparent to those of ordinary skill in the art upon readingthe foregoing description. The inventor expects skilled artisans toemploy such variations as appropriate, and the inventors intend for thepresent invention to be practiced otherwise than specifically describedherein. Accordingly, the present invention includes all modificationsand equivalents of the subject matter recited in the claims appendedhereto as permitted by applicable law. Moreover, any combination of theabove-described elements in all possible variations thereof isencompassed by the present invention unless otherwise indicated hereinor otherwise clearly contradicted by context.

Furthermore, references may have been made to patents and printedpublications in this specification. Each of the above-cited referencesand printed publications are individually incorporated herein byreference in their entirety.

Specific embodiments disclosed herein may be further limited in theclaims using consisting of or and consisting essentially of language.When used in the claims, whether as filed or added per amendment, thetransition term “consisting of” excludes any element, step, oringredient not specified in the claims. The transition term “consistingessentially of” limits the scope of a claim to the specified materialsor steps and those that do not materially affect the basic and novelcharacteristic(s). Embodiments of the present invention so claimed areinherently or expressly described and enabled herein.

In closing, it is to be understood that the embodiments of the presentinvention disclosed herein are illustrative of the principles of thepresent invention. Other modifications that may be employed are withinthe scope of the present invention. Thus, by way of example, but not oflimitation, alternative configurations of the present invention may beutilized in accordance with the teachings herein. Accordingly, thepresent invention is not limited to that precisely as shown anddescribed.

What is claimed is:
 1. An implantable device that controls the movementof fluid to an inflatable portion of a gastric band, the implantabledevice comprising: a body having an inlet, an outlet and a valve seatpositioned between the inlet and the outlet, the valve seat being influid communication with the inlet and the outlet, the body defining afluid passage from the inlet to the outlet; a valve seal having one ormore edges coupled to the body, the valve seal being made of anelastomeric material, wherein the valve seal is directly seated on thevalve seat in a closed position that blocks fluid communication betweenthe inlet and the outlet, and wherein the valve seal is not seated onthe valve seat in an open position that does not block the valve seatand does not block fluid communication between the inlet and the outlet;and an actuator including an actuator body defining a threaded screwhole and positioned within the body and a screw positioned within thethreaded screw hole, the screw configured to apply a force on the valveseal causing the valve seal to move from the open position to the closedposition when the actuator receives a telemetric signal from a remotetransmitter.
 2. The implantable device of claim 1 further comprising amotor, positioned within the actuator body, for moving the screw withinthe threaded screw hole.
 3. The implantable device of claim 2 whereinthe motor is selected from a group consisting of a DC motor, an ACmotor, a solenoid, a stepper motor, a piezoelectric actuator, apiezoelectric driver, an electroactive polymer, and combinationsthereof.
 4. The implantable device of claim 3 wherein the motor isconfigured to move the screw to a first screw position so that the valveseal can be moved to a first valve seal position depending on thetelemetric signal received from the remote transmitter.
 5. Theimplantable device of claim 4 wherein the first valve seal position isselected from a group consisting of the closed position, the openposition, and a partially-open position which is between the closedposition and the open position.
 6. The implantable device of claim 1further comprising a coupling mechanism, positioned between the valveseal and the screw, for decoupling a rotational motion of the screw butallowing for a translational motion of the screw.
 7. The implantabledevice of claim 6 wherein the coupling mechanism is selected from agroup consisting of a tappet, a ball bearing, a bellows unit, andcombinations thereof.
 8. The implantable device of claim 1 furthercomprising a flow sensor, coupled to the valve seat, for determining andadjusting an amount of the fluid flowing between the inlet and theoutlet.
 9. The implantable device of claim 1 further comprising apressure sensor, coupled to the valve seat, for determining andadjusting a pressure of the fluid flowing between the inlet and theoutlet.
 10. The implantable device of claim 1 wherein the remotetransmitter transmits the telemetric signal to the actuator.
 11. Amethod of controlling an implantable device that controls the movementof fluid to an inflatable portion of a gastric band, the methodcomprising: providing an implantable device that includes: a body havingan inlet, an outlet and a valve seat positioned between the inlet andthe outlet, the valve seat being in fluid communication with the inletand the outlet, the body defining a fluid passage from the inlet to theoutlet, a valve seal having one or more edges coupled to the body, thevalve seal being made of an elastomeric material, wherein the valve sealis directly seated on the valve seat in a closed position that blocksfluid communication between the inlet and the outlet, and wherein thevalve seal is not seated on the valve seat in an open position that doesnot block the valve seat and does not block fluid communication betweenthe inlet and the outlet, and an actuator including an actuator bodydefining a threaded screw hole and positioned within the body and ascrew positioned within the threaded screw hole, the screw configured toapply a force on the valve seal causing the valve seal to move from theopen position to the closed position when the actuator receives atelemetric signal from a remote transmitter; receiving the telemetricsignal; and responsive to the telemetric signal, turning the screw inone of two rotational directions.
 12. The method according to claim 11,wherein turning the screw in a first rotational direction increases aforce on the valve seal to close the valve and turning the screw in asecond rotational direction opposite the first rotational directiondecreases the force on the valve seal to open the valve.
 13. The methodaccording to claim 11, wherein turning the screw in a first rotationaldirection increases a force on the valve seal to displace the valve sealin a direction towards the closed position and turning the screw in asecond rotational direction opposite the first rotational directiondecreases the force on the valve seal to displace the valve seal in adirection towards the open position.
 14. The method according to claim11, wherein turning the screw in a first rotational direction translatesthe screw and the valve seal in a direction towards the valve seat, andturning the screw in a second rotational direction opposite the firstrotational direction translates the screw and the valve seal in adirection away from the valve seat.